JP4462394B2 - Silicon film pattern forming method - Google Patents

Description

【０００９】
上記の如きポリシラン化合物は単独であるいは２種以上を混合して使用することができる。
本発明において、これらのポリシラン化合物は溶媒に溶解されて塗布溶液に調製される。使用される溶媒としては、ポリシラン化合物を溶解しそしてポリシラン化合物と反応しないものであれば特に限定されず、例えば、ｎ−ペンタン、ｎ−ヘキサン、ｎ−ヘプタン、ｎ−オクタン、デカン、ジシクロペンタン、ベンゼン、トルエン、キシレン、デュレン、インデン、テトラヒドロナフタレン、デカヒドロナフタレン、スクワランなどの炭化水素系溶媒；ジエチルエーテル、ジプロピルエーテル、エチレングリコールジメチルエーテル、エチレングリコールジエチルエーテル、エチレングリコールメチルエチルエーテル、ジエチレングリコールジメチルエーテル、ジエチレングリコールジエチルエーテル、ジエチレングリコールメチルエチルエーテル、テトラヒドロフランテトラヒドロピラン、１,２−ジメトキシエタン、ビス（２−メトキシエチル）エーテル、ｐ−ジオキサン、テトラヒドロフランなどのエーテル系溶媒；およびプロピレンカーボネート、γ−ブチロラクトン、Ｎ−メチル−２−ピロリドン、ジメチルホルムアミド、アセトニトリル、ジメチルスルホキシド、塩化メチレン、クロロホルムなどの極性溶媒を挙げることができる。これらのうち、ポリシラン化合物、特に、環状ケイ素化合物の溶解性と該溶液の安定性の点で炭化水素系溶媒、エーテル系溶媒が好ましく、炭化水素系溶媒がさらに好ましい。これらの溶媒は、単独でも、あるいは２種以上の混合物としても使用できる。
【００１０】
上記ポリシラン化合物の溶液の濃度は、好ましくは１〜５０重量％である。濃度は所望のシリコン膜厚に応じて適宜調製することができる。これらの溶液には、目的とする機能を損なわない範囲で必要に応じてフッ素系、シリコーン系、非イオン系などの表面張力調節剤（界面活性剤）を少量添加することができる。
かくして得られたポリシラン溶液には、必要に応じて酸化アルミニウム、酸化ジルコニウム、酸化チタン、酸化ケイ素などの金属酸化物の微粒子などを適宜混合して使用することができる。また、溶液の塗布対象物への濡れ性を良好化し、塗布した膜のレベルリング性を改良し、塗膜のぶつぶつの発生、ゆず肌の発生などを防止するため非イオン性界面活性剤などを使用することができる。
【００１１】
かくして得られた溶液組成物を支持体上に塗布してポリシランからなる塗膜を形成する。支持体の材質、形状等は特に制限はないが、材質は次工程の熱処理に耐えられるものが好ましく、また塗膜を形成する支持体面は平面であるのが好ましいがその形態は特に限定されるものではない。これらの支持体の材質の具体例としては、ガラス、金属、プラスチック、セラミックスなどを挙げることができる。ガラスとしては、例えば石英ガラス、ホウ珪酸ガラス、ソーダガラス、鉛ガラスが使用できる。金属としては、例えば金、銀、銅、ニッケル、シリコン、アルミニウム、鉄の他ステンレス鋼などが使用できる。プラスチックとしては、例えばポリイミド、ポリエーテルスルホンなどが使用できる。これらの材質からなる支持体の形態はバルク形状、板状、フィルム形状などで特に制限されるものではない。また、上記溶液の塗布に際しては、塗布方法は特に限定されずスピンコート、ディップコート、カーテンコート、ロールコート、スプレーコート、インクジェット法などにより実施することができる。塗布は１回で、または複数回、重ね塗りすることもできる。好適な塗膜の厚みは固形分濃度に依存して適宜変動するが、固形分として０．０１〜１００μｍが好ましく、０．１〜１０μｍであるのがさらに好ましい。
【００１２】
得られたポリシラン化合物の塗膜は、熱処理に付されアモルファスシリコン膜に変換される。熱処理については、その温度を、３００℃以上とするのが好ましく、４００℃〜５００℃とするのがさらに好ましい。加熱時間は３０秒から３０分程度で十分である。また、加熱雰囲気は不活性の雰囲気例えば窒素、ヘリウム、アルゴンなどからなる雰囲気が好ましい。これらは必要に応じて水素などの還元性ガスを含ませてもよい。
【００１３】
本発明のアモルファスシリコン膜は、上記▲１▼および▲２▼の性質を有するため、これを酸素を含有する雰囲気中で光処理することにより酸化シリコン膜を得ることができ、またこれを不活性雰囲気中で光処理することにより多結晶のポリシリコン膜を得ることができる。また、上記光処理の際に、マスクパターンを介して光処理を実施することにより、それぞれアモルファスシリコンと酸化シリコンからなるパターンおよびアモルファスシリコンとポリシリコンからなるパターンを形成することができる。さらに、アモルファスシリコンと酸化シリコンからなるパターンを次いで不活性雰囲気中で光処理することによりポリシリコンと酸化シリコンからなるパターンを形成することができる。また、アモルファスシリコンとポリシリコンからなるパターンを次いで酸素を含有する雰囲気中で光処理することにより、同様に、ポリシリコンと酸化シリコンからなるパターンを形成することができる。
【００１４】
さらに別の態様として、アモルファスシリコンと酸化シリコンからなるパターンを不活性雰囲気中で光処理する際に、あるいはアモルファスシリコンとポリシリコンからなるパターンを酸素を含有する雰囲気中で光処理する際に、アモルファスシリコン膜部にマスクパターンを介して光照射することにより、アモルファスシリコンと酸化シリコンとポリシリコンからなるパターンを形成することができる。
【００１５】
アモルファスシリコンをポリシリコンあるいは酸化シリコンに変換する際に使用される光源としては、前記光源と同じものを使用することができるが、特にレーザー光であることが好ましい。光の波長は通常１７０ｎｍ〜６００ｎｍが好ましく。特に好ましくは２４０〜５５０ｎｍのレーザー光である。光照射する際の雰囲気は、酸素を含有する雰囲気あるいは不活性雰囲気であり、不活性雰囲気としては、例えば窒素、アルゴン、ヘリウムの如き不活性ガスの雰囲気が挙げられる。また、酸素を含有する雰囲気としては、例えば、上記の如き不活性ガスと分子状酸素との混合気体を上げることができる。酸素の濃度はアモルファスシリコンが酸化シリコンになるのに必要な量があればよいが、通常１ｐｐｍ〜５０％である。
【００１６】
かくして、本発明によれば、下記（ハ）〜（ニ）のパターン化された膜が得られる。これらの膜の特徴は異なる物質からなる少なくとも２つの領域の表面が連続した同一平面を形成している点にある。
（ハ） ポリシリコン領域と酸化シリコン領域からなり、これらの２つの領域で一定のパターンが形成されており、そしてこれらの２つの領域の表面は連続した同一平面を形成している、パターン化されたポリシリコン領域と酸化シリコン領域からなる膜。
（ニ） ポリシリコン領域、酸化シリコン領域およびアモルファスシリコン領域からなり、これらの３つの領域で一定のパターンが形成されており、そしてこれらの３つの領域の表面は連続した同一平面を形成している、パターン化されたポリシリコン領域、酸化シリコン領域およびアモルファスシリコン領域からなる膜。
【００１７】
【実施例】
以下に、本発明を下記実施例により詳細に説明するが、本発明はこれら実施例に限定されるものではない。
【００１８】
合成例１
温度計、コンデンサー、滴下ロートおよび攪拌装置を取り付けた内容量が２Ｌの４つ口フラスコ内をアルゴンガスで置換した後、乾燥したテトラヒドロフラン１．５Ｌとリチウム金属２７．４ｇを仕込み、アルゴンガスでバブリングした。この懸濁液に、氷冷下で攪拌しながら、ジフェニルジクロルシラン５００ｇを滴下ロートより添加した。リチウム金属が完全に消失するまで反応を続けた後、反応混合物を氷水中に注ぎ反応生成物を沈殿させた。この沈殿物を濾別し、水で良く洗浄した後シクロヘキサンで洗浄し２０８ｇの粗生成物を得た。この粗生成物は高速液体クロマトグラフィーで分析したところ、デカフェニルシクロペンタシランとウンデカフェニルシクロヘキサシランの混合物でその混合比は１０／１（重量比）であった。次にアルゴンガスで置換した３ｌのフラスコに上記の粗生成物１９０ｇおよびトルエン２，０００ｍｌを仕込み、塩化アルミニウム１５ｇを加え、塩化水素ガスを導入した。ＮＭＲスペクトルでフェニル基が塩素に置換されたのを確認後、氷冷下アルゴン雰囲気中で塩素原子１個に対して１等量のリチウムアルミニウムヒドリドを加えて還元反応を行った。反応で生じたアルミニウム化合物を除去することにより還元されたシラン化合物１６ｇを得た。このものはマス、²⁹Ｓｉ−ＮＭＲおよびＩＲの各スペクトルとガスクロマトグラフィーによりＳｉ₅Ｈ₁₀（シクロペンタシラン）とＳｉ₆Ｈ₁₂の混合物（重量比で１０／１）であることが判明した。
【００１９】
合成例２
温度計、コンデンサー、滴下ロートおよび攪拌装置を取り付けた内容量が３Ｌの４つ口フラスコ内をアルゴンガスで置換した後、乾燥したテトラヒドロフラン２Ｌとリチウム金属７５ｇを仕込み、アルゴンガスでバブリングした。この懸濁液を０℃で攪拌しながらフェニルトリクロルシラン５００ｇを滴下ロートより添加した。リチウム金属が完全に消失するまで０℃で反応を続けた後、室温でさらに１２時間攪拌した。黒褐色の反応混合物を氷水に注ぎ反応生成物を沈殿させた。この沈殿物を濾別し、水で良く洗浄した後真空乾燥することによりフェニル基を有する多環状ケイ素化合物２１０ｇを得た。このフェニル基を有するポリシラン化合物１５０ｇをトルエン２Ｌに懸濁させ、塩化アルミニウム５ｇを加えた後、これに乾燥した塩化水素ガスを反応系が透明になるまで導入した。反応終了後、アルミニウム化合物を除去した後、溶媒を減圧下で留去し脱フェニルクロル化された多環状ケイ素化合物の粗生成物８５ｇを得た。このクロル体を精製することなく、アルゴン雰囲気中でジエチルエーテル２５０ｍｌとトルエン２５０ｍｌの混合溶媒に溶解し、０℃で攪拌しながらリチウムアルミニウムヒドリド１５ｇを加えさらに３時間攪拌を続けた後、徐々に室温まで上げさらに６時間攪拌を続けた。反応混合物からアルミニウム化合物を濾別した後、濾液を濃縮し精製することにより目的の水素化されたポリシラン化合物（Ｓｉ₆Ｈ₆）２１ｇを得た。
【００２０】
参考例１
上記合成例１で得られたポリシラン化合物（混合物）４ｇをベンゼン１０ｇに溶かし溶液を調製した。ディップコートにより石英基板にアルゴン雰囲気下で塗布した。この塗布基板をアルゴン雰囲気中で溶媒を蒸発させた後、５００℃にて５分間加熱すると基板上には金属光沢を有するシリコン膜が残留した。このシリコン膜の膜厚は１，５００オングストロームであった。このシリコン膜のＥＳＣＡスペクトルを測定したところ、Ｓｉ_２ｐ軌道に帰属されるピークが９９ｅＶに観察された。またこのシリコン膜のラマン散乱スペクトルから、１００％アモルファス状態であった。このアモルファス状態のシリコン膜にＸｅＣｌエキシマレーザー（３０８ｎｍ）を窒素中で３００ｍＪ／ｃｍ^２照射したところ、照射部が黄色になった。黄変したレーザー照射部についてＥＳＣＡとラマンスペクトルを測定したところ、ＥＳＣＡでは変化がみられなかったが、ラマンスペクトルで５２０ｃｍ^−１にシャープなピークが現れポリシリコンであることが分った。このＥＳＣＡスペクトルを図１に示す。
【００２１】
参考例２
上記参考例１で塗布、焼成して得られたアモルファスシリコン膜を用い、レーザー照射雰囲気を窒素中から空気中に替え、他は実施例１と同様にして照射したところ、照射部が無色透明に変化した。この無色透明部のＥＳＣＡスペクトルはＳｉ_２ｐ軌道に帰属されるピークが１０６ｅＶに観察され、同時に５３６ｅＶにＯ_１ｓに帰属されるピークが観察され、ケイ素と酸素の元素組成比はＳｉＯ_２であった。図２に無色透明部のＥＳＣＡスペクトルを示した。
【００２２】
参考例３
市販のプラズマＣＤＶ装置を用いて、０．１Ｔｏｒｒの減圧下でシリコンの原料ガスとしてモノシランガスとアルゴンガスの混合ガス（モノシランが５体積％）を１５０ｓｃｃｍの流量で供給しながら、２５ｗａｔｔｓのＲＦプラズマ中で４５０℃に加熱した石英基板上に６００オングストロームの膜厚の赤銅色のシリコン膜を堆積させた。このシリコン膜はＥＳＣＡおよびラマンスペクトルからアモルファス状のシリコン膜であった。このアモルファスシリコン膜を窒素中で波長が３０８ｎｍのＸｅＣｌエキシマレーザーを２３０ｍＪ／ｃｍ^２照射したところ、照射部が黄色に変色した。このレーザー照射部のＥＳＣＡおよびラマンスペクトルを測定したところ、ＥＳＣＡでは９９ｅＶにシャープなピークのみが観察されＳｉＯ_２に帰属される１０６ｅＶにはピークは観察されなかった。また、ラマンスペクトルでは５２０ｃｍ^−１にシャープなピークが観察され、結晶化率が９５％のポリシリコンであった。
【００２３】
比較例１
上記参考例３のレーザー照射雰囲気を窒素中から空気中に替え、他は参考例３と同様にして波長が３０８ｎｍのＸｅＣｌエキシマレーザーを２３０ｍＪ／ｃｍ^２照射した。参考例３と全く同様に照射部が黄色に変色した。このレーザー照射部について、ＥＳＣＡとラマンスペクトルを測定した結果は参考例３で得られたものと同じものであり、ＳｉＯ_２に帰属されるピークは観察されなかった。
【００２４】
参考例４
上記合成例１で得られたポリシラン化合物（混合物）４ｇをトルエン１０ｇに溶かし溶液を調製した。スピンコートにより石英基板にアルゴン雰囲気下で塗布した。この塗布基板をアルゴン雰囲気中で５００℃にて５分間加熱すると基板上には金属状のシリコン膜が残留した。このシリコン膜の膜厚は７５０オングストロームであった。このシリコン膜のＥＳＣＡスペクトルを測定したところ、Ｓｉ_２ｐ軌道に帰属されるピークが９９ｅＶに観察された。またこのシリコン膜のラマン散乱スペクトルから、１００％アモルファス状態であった。このアモルファス状態のシリコン膜にＸｅＣｌエキシマレーザー（３０８ｎｍ）を所望のパターンを有するマスクを介して空気中で３００ｍＪ／ｃｍ^２照射したところ、照射部が透明になり透明部と不透明部のマスクと同じパターンが得られた。レーザー照射して透明になった照射部を顕微鏡観察した結果、クラックなどの膜異常は認められず良質の透明膜であった。またこの部分の膜厚は７５０オングストロームであった。またＥＳＣＡスペクトルを測定したところ、Ｓｉ_２ｐ軌道に帰属されるピークが１０６ｅＶに、またＯ_１ｓ軌道に帰属されるピークが５３６ｅＶに観察され、それらの元素組成比はＳｉＯ_２であった。さらにこの照射部と未照射部を有するパターン基板の両者の境界付近の表面状態をα―ｓｔｅｐ（Ｔｅｎｃｏｒ Ｉｎｓｔｒｕｍｅｎｔｓ社製）で測定したところ殆ど平坦であった。
【００２５】
実施例１
参考例４で得られたアモルファスシリコン／酸化シリコンのパターンの未照射部（アモルファスシリコン）に、さらに不活性雰囲気中で、レーザーを照射してポリシリコン／酸化シリコンのパターンを形成した。
この表板の表面状態をα−ステップで観察したところ、参考例４と同様に全く平坦であった。このときのα−ステップのチャートを図３に示す。
【００２６】
実施例２
上記合成例１で得られたポリシラン化合物２ｇと合成例２で得られたポリシラン化合物２ｇとをトルエン３６ｇに溶かした溶液を調製した。この溶液を用いて参考例１と同様にして膜厚１５００オングストロームの金属光沢を有するシリコン膜を作成した。このシリコン膜はラマンスペクトルから１００％アモルファス状であった。このアモルファスシリコン膜を窒素雰囲気中で波長が５３２ｎｍのＮｄＹＡＧレーザーを２５０ｍＪ／ｃｍ^２照射したところ、照射部が黄変した。この黄変部をＥＳＣＡスペクトルおよびラマンスペクトルの測定結果から、結晶化率が８０％のポリシリコンであることが判った。さらにこの基板を空気の雰囲気中で上記未照射部に５３２ｎｍのＮｄＹＡＧレーザーを３００ｍＪ／ｃｍ^２照射したところ、照射部が無色透明になった。この無色透明部をＥＳＣＡで分析したところＳｉ_２ｐ軌道に帰属されるピークが１０６ｅＶに観察されＳｉＯ_２であった。かくして得られた基板は同一面内にアモルファスシリコン部とポリシリコン部と酸化シリコンからなるものであった。この基板の表面状態をα―ｓｔｅｐで観察したところ、実施例１と同様に殆ど平坦であった。
【図面の簡単な説明】
【図１】 参考例１におけるポリシリコン膜のＥＳＣＡスペクトル図である。
【図２】 参考例２における無色透明部（酸化ケイ素）のＥＳＣＡスペクトル図である。
【図３】 実施例１で得られたポリシリコン／酸化シリコンからなる膜の表面の平坦性を示す図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pattern forming method using the amorphous silicon film with unique properties. More specifically , using an amorphous silicon film that exhibits unique properties by light irradiation, it is useful for LSI, thin film transistors, photoelectric conversion devices, etc. Semiconductor silicon films and electrical insulator films, dielectric films, protective films, or optics It relates to how to form a pattern on having a useful silicon oxide film as a device.
[0002]
[Prior art]
Silicon oxide has characteristics such as excellent light transmittance and electrical insulation, as represented by quartz, and is used in many optical applications and electronic devices. On the other hand, it goes without saying that silicon is an indispensable material for electronic devices as a semiconductor. A structure made of silicon oxide and silicon having such excellent characteristics has been pointed out as a novel device which has not been heretofore known. For example, Appl. Phys. Lett. 56 , 2379 (1990), it is reported that micro-sized silicon particles whose surfaces are covered with silicon oxide emit visible light, and SCIENCE Vol. 262 No. 19 1242 (1993) reports that the emission wavelength varies depending on the size of the surface silicon oxide particles. In addition, Material Integration Vol. 12 No. 273 (1999) pointed out a large band discontinuity at the silicon / silicon oxide interface. Based on this feature, the possibility of device applications such as single-electron / visible light emission quantum wells and the large silicon / silicon oxide interface It has been pointed out that it can be applied to optical waveguides using the difference in refractive index. However, in order to form a fine silicon / silicon oxide structure that exhibits these performances, conventionally, there is only a method that requires high energy, such as a method that combines Si molecular beam epitaxy and oxygen ion implantation, and the substrate. However, a device that can only form a structure that is stacked in the vertical direction with respect to the above, and has not yet been realized. On the other hand, the aforementioned material integration magazine reports on the formation of fine wiring by implanting oxygen ions into a Si substrate patterned along the crystal plane direction as an example of horizontal patterning. However, this technique not only requires high energy, but also has a limit that the degree of freedom of wiring is limited because the wiring pattern depends on the crystal structure of Si as a substrate.
[0003]
[Problems to be solved by the invention]
It is an object of the present invention to provide an amorphous silicon film having a unique property that can be easily converted into silicon oxide or polysilicon , particularly silicon / oxide patterned in the horizontal direction as well as in the vertical direction with respect to the substrate. to provide a method of forming any pattern comprising one of an amorphous silicon film or al least silicon oxide and polysilicon silicon structure can be easily formed.
Still another object of the present invention is to provide a method of forming a patterned film containing at least two of a silicon oxide region, a polysilicon region, and an amorphous silicon region.
Still other objects and advantages of the present invention will become apparent from the following description.
[0004]
[Means for Solving the Problems]
According to the present invention, the above-mentioned objects and advantages of the present invention include, firstly, the property that a silicon oxide film is formed when light-treated in an oxygen-containing atmosphere and a polysilicon film is formed when light-treated in an inert atmosphere. This is achieved by a method of forming a silicon oxide film obtained by photoprocessing an amorphous silicon film in an oxygen-containing atmosphere or a polysilicon film obtained by photoprocessing in an inert atmosphere.
Further, according to the present invention, the above objects and advantages of the present invention, the second, the amorphous silicon film, not (i) oxygen through a mask pattern in an atmospheric containing an operation of the optical processing (ii) This is achieved by a method of forming a pattern of at least two of polysilicon, silicon oxide and amorphous silicon by performing at least one of the operations of photoprocessing through a mask pattern in an active atmosphere.
[0005]
Furthermore, according to the present invention, at least two regions of the polysilicon region, the silicon oxide region, and the amorphous silicon region are formed, and a fixed pattern is formed in these at least two regions, and at least two of these regions are formed. The surface of the region forms a continuous and coplanar surface. This is achieved by a method for forming a film comprising at least two regions.
In addition, the same plane in this invention means the plane which exists in the range of a coating-film formation precision.
The present invention is described in detail below.
The amorphous silicon film of the present invention has (1) the property of becoming a silicon oxide film when phototreated in an atmosphere containing oxygen and (2) the property of becoming a polysilicon film when phototreated in an inert atmosphere.
[0006]
Such an amorphous silicon film can be prepared, for example, by preparing a solution composition containing a polysilane compound, applying the solution composition to the support surface, and then heat-treating the obtained polysilane compound coating film. .
The polysilane compound used in the present invention has the following formula SinRm
Here, R is a hydrogen atom or a halogen atom, n is an integer of 3 or more, and m is an integer of n to 2n.
It is represented by
As the halogen atom, for example, fluorine, chlorine, bromine and the like are preferable.
As the polysilane compound of the above formula, a cyclic silicon compound in which n is 5 to 20 is preferable in terms of thermodynamic stability, solubility, ease of purification, and the like of the polysilane compound. When n is smaller than 5, the polysilane compound itself becomes unstable due to distortion caused by the ring, which causes a difficulty in handling. On the other hand, when n is larger than 20, a decrease in solubility due to the cohesive force of the silicon compound is recognized, and the selection of the solvent to be used is narrowed.
[0007]
Specific examples of the polysilane compound used in the present invention include, as a compound of m = 2n, cyclotrisilane, cyclotetrasilane, cyclopentasilane, silylcyclopentasilane, cyclohexasilane, silylcyclohexasilane, and cycloheptasilane. And polysilane compounds having a single ring system such as hexachlorocyclotrisilane, trichlorocyclotrisilane, octachlorocyclotetrasilane, tetrachlorocyclotetrasilane, deca Chlorcyclopentasilane, pentachlorocyclopentasilane, dodecachlorocyclohexasilane, hexachlorocyclohexasilane, tetradecachlorocycloheptasilane, heptachlorocycloheptasilane, hexabromocyclotri Lan, tribromocyclotrisilane, pentabromocyclotrisilane, tetrabromocyclotrisilane, octabromocyclotetrasilane, tetrabromocyclotetrasilane, decabromocyclopentasilane, pentabromocyclopentasilane, dodecabromocyclohexasilane, Examples thereof include halogenated cyclic silicon compounds such as hexabromocyclohexasilane, tetradecabromocycloheptasilane, and heptabromocycloheptasilane. Specific examples of the compound where m = 2n-2 include 1,1′-biscyclobutasilane, 1,1′-biscyclopentasilane, 1,1′-biscyclohexasilane, 1,1 ′. -Biscycloheptasilane, 1,1'-cyclobutasilylcyclopentasilane, 1,1'-cyclobutasilylcyclohexasilane, 1,1'-cyclobutasilylcycloheptasilane, 1,1'-cyclopentasilyl Cyclohexasilane, 1,1′-cyclopentasilylcycloheptasilane, 1,1′-cyclohexasilylcycloheptasilane, spiro [2,2] pentasilane, spiro [3,3] heptatasilane, spiro [4,4] Nonasilane, spiro [4,5] decasilane, spiro [4,6] undecasilane, spiro [5,5] undecasilane, spiro [5,6] dodecasilane, spiro (B) Silicon hydride compounds having two ring systems such as [6,6] tridecasilane, and silicon compounds in which some or all of these hydrogen atoms are substituted with SiH ₃ groups or halogen atoms. Specific examples of the compound in which m = n include a silicon hydride compound having a polycyclic system such as compounds 1 to 5 of the following formula, and a part or all of these hydrogen atoms are partially SiH ₃ groups. And silicon compounds substituted with halogen atoms.
[0008]
[Chemical 1]

[0009]
The above polysilane compounds can be used alone or in admixture of two or more.
In the present invention, these polysilane compounds are dissolved in a solvent to prepare a coating solution. The solvent to be used is not particularly limited as long as it dissolves the polysilane compound and does not react with the polysilane compound. For example, n-pentane, n-hexane, n-heptane, n-octane, decane, dicyclopentane. Hydrocarbon solvents such as benzene, toluene, xylene, durene, indene, tetrahydronaphthalene, decahydronaphthalene, squalane; diethyl ether, dipropyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether , Diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, tetrahydrofuran tetrahydropyran, 1,2-dimethoxyethane, bis (2 -Methoxyethyl) ether solvents such as ether, p-dioxane and tetrahydrofuran; and polar solvents such as propylene carbonate, γ-butyrolactone, N-methyl-2-pyrrolidone, dimethylformamide, acetonitrile, dimethyl sulfoxide, methylene chloride and chloroform. Can be mentioned. Of these, hydrocarbon solvents and ether solvents are preferable, and hydrocarbon solvents are more preferable in terms of the solubility of the polysilane compound, particularly the cyclic silicon compound, and the stability of the solution. These solvents can be used singly or as a mixture of two or more.
[0010]
The concentration of the polysilane compound solution is preferably 1 to 50% by weight. The concentration can be appropriately adjusted according to the desired silicon film thickness. A small amount of a surface tension regulator (surfactant) such as a fluorine-based, silicone-based, or nonionic-based one can be added to these solutions as long as the target function is not impaired.
In the polysilane solution thus obtained, fine particles of metal oxides such as aluminum oxide, zirconium oxide, titanium oxide, and silicon oxide can be appropriately mixed and used as necessary. In order to improve the wettability of the solution to the application object, improve the leveling property of the applied film, and prevent non-ionic surfactants etc. to prevent the occurrence of coating crushing and distortion skin. Can be used.
[0011]
The solution composition thus obtained is applied onto a support to form a coating film made of polysilane. The material, shape, etc. of the support are not particularly limited, but the material is preferably one that can withstand the heat treatment of the next step, and the support surface on which the coating film is formed is preferably a flat surface, but its form is particularly limited. It is not a thing. Specific examples of the material for these supports include glass, metal, plastic, and ceramics. As glass, for example, quartz glass, borosilicate glass, soda glass, and lead glass can be used. As the metal, for example, gold, silver, copper, nickel, silicon, aluminum, iron, and stainless steel can be used. As the plastic, for example, polyimide, polyethersulfone and the like can be used. The form of the support made of these materials is not particularly limited by a bulk shape, a plate shape, a film shape, or the like. In addition, when the solution is applied, the application method is not particularly limited, and the solution can be applied by spin coating, dip coating, curtain coating, roll coating, spray coating, an inkjet method, or the like. The application may be performed once or multiple times. Although the suitable thickness of a coating film changes suitably depending on solid content concentration, 0.01-100 micrometers is preferable as solid content, and it is more preferable that it is 0.1-10 micrometers.
[0012]
The obtained polysilane compound coating film is subjected to a heat treatment to be converted into an amorphous silicon film. About heat processing, it is preferable that the temperature shall be 300 degreeC or more, and it is more preferable to set it as 400 to 500 degreeC. A heating time of about 30 seconds to 30 minutes is sufficient. The heating atmosphere is preferably an inert atmosphere such as nitrogen, helium, or argon. These may contain a reducing gas such as hydrogen as necessary.
[0013]
Since the amorphous silicon film of the present invention has the properties (1) and (2) above, a silicon oxide film can be obtained by subjecting it to light treatment in an atmosphere containing oxygen, and this is inactive. A polycrystalline polysilicon film can be obtained by light treatment in an atmosphere. In addition, by performing optical processing through a mask pattern during the optical processing, it is possible to form a pattern made of amorphous silicon and silicon oxide and a pattern made of amorphous silicon and polysilicon, respectively. Further, a pattern made of polysilicon and silicon oxide can be formed by photo-processing the pattern made of amorphous silicon and silicon oxide in an inert atmosphere. Similarly, a pattern made of polysilicon and silicon oxide can be formed by subjecting a pattern made of amorphous silicon and polysilicon to light treatment in an atmosphere containing oxygen.
[0014]
As yet another aspect, when a pattern made of amorphous silicon and silicon oxide is light-treated in an inert atmosphere, or a pattern made of amorphous silicon and polysilicon is light-treated in an atmosphere containing oxygen, it is amorphous. By irradiating the silicon film portion with light through a mask pattern, a pattern made of amorphous silicon, silicon oxide, and polysilicon can be formed.
[0015]
As a light source used for converting amorphous silicon into polysilicon or silicon oxide, the same light source as that described above can be used, but laser light is particularly preferable. The wavelength of light is usually preferably 170 nm to 600 nm. Particularly preferred is a laser beam of 240 to 550 nm. The atmosphere at the time of light irradiation is an atmosphere containing oxygen or an inert atmosphere, and examples of the inert atmosphere include an atmosphere of an inert gas such as nitrogen, argon, or helium. As the atmosphere containing oxygen, for example, a mixed gas of the above inert gas and molecular oxygen can be raised. The oxygen concentration may be an amount necessary for the amorphous silicon to become silicon oxide, but is usually 1 ppm to 50%.
[0016]
Thus, according to the present invention, the following patterned films (c) to (d) are obtained. The characteristics of these films are Ru near the point which forms the same plane surface are continuous in at least two regions made of different materials.
(C) A pattern consisting of a polysilicon region and a silicon oxide region, in which a constant pattern is formed in these two regions, and the surfaces of these two regions form a continuous and coplanar surface. A film comprising a polysilicon region and a silicon oxide region.
(D) It consists of a polysilicon region, a silicon oxide region, and an amorphous silicon region, and a fixed pattern is formed in these three regions, and the surfaces of these three regions form a continuous and identical plane. A film comprising a patterned polysilicon region, a silicon oxide region and an amorphous silicon region.
[0017]
【Example】
EXAMPLES The present invention will be described in detail below with reference to the following examples, but the present invention is not limited to these examples.
[0018]
Synthesis example 1
After replacing the inside of a 4 L flask with a 2 L capacity equipped with a thermometer, condenser, dropping funnel and stirrer with argon gas, 1.5 L of dry tetrahydrofuran and 27.4 g of lithium metal were charged and bubbled with argon gas did. To this suspension, 500 g of diphenyldichlorosilane was added from a dropping funnel while stirring under ice cooling. The reaction was continued until the lithium metal completely disappeared, and then the reaction mixture was poured into ice water to precipitate the reaction product. This precipitate was separated by filtration, washed well with water and then washed with cyclohexane to obtain 208 g of a crude product. When this crude product was analyzed by high performance liquid chromatography, it was a mixture of decaphenylcyclopentasilane and undecaphenylcyclohexasilane, and the mixing ratio was 10/1 (weight ratio). Next, 190 g of the above crude product and 2,000 ml of toluene were charged into a 3 l flask purged with argon gas, 15 g of aluminum chloride was added, and hydrogen chloride gas was introduced. After confirming that the phenyl group was replaced with chlorine by NMR spectrum, a reduction reaction was performed by adding 1 equivalent of lithium aluminum hydride to one chlorine atom in an argon atmosphere under ice cooling. By removing the aluminum compound produced by the reaction, 16 g of a reduced silane compound was obtained. This was found to be a mixture of Si ₅ H ₁₀ (cyclopentasilane) and Si ₆ H ₁₂ (weight ratio 10/1) by mass, ²⁹ Si-NMR and IR spectra and gas chromatography.
[0019]
Synthesis example 2
After replacing the inside of the 3 L four-necked flask equipped with a thermometer, a condenser, a dropping funnel and a stirrer with argon gas, 2 L of dried tetrahydrofuran and 75 g of lithium metal were charged and bubbled with argon gas. While stirring this suspension at 0 ° C., 500 g of phenyltrichlorosilane was added from a dropping funnel. The reaction was continued at 0 ° C. until the lithium metal completely disappeared, and then the mixture was further stirred at room temperature for 12 hours. The blackish brown reaction mixture was poured into ice water to precipitate the reaction product. The precipitate was separated by filtration, washed well with water and then vacuum dried to obtain 210 g of a polycyclic silicon compound having a phenyl group. 150 g of this polysilane compound having a phenyl group was suspended in 2 L of toluene, 5 g of aluminum chloride was added, and then dry hydrogen chloride gas was introduced thereto until the reaction system became transparent. After completion of the reaction, the aluminum compound was removed, and then the solvent was distilled off under reduced pressure to obtain 85 g of a crude product of a polycyclic silicon compound which was dephenylchlorinated. This chloro compound was dissolved in a mixed solvent of 250 ml of diethyl ether and 250 ml of toluene in an argon atmosphere without purification, 15 g of lithium aluminum hydride was added with stirring at 0 ° C., and stirring was further continued for 3 hours. The mixture was further stirred for 6 hours. The aluminum compound was filtered off from the reaction mixture, and the filtrate was concentrated and purified to obtain 21 g of the target hydrogenated polysilane compound (Si ₆ H ₆ ).
[0020]
Reference example 1
A solution was prepared by dissolving 4 g of the polysilane compound (mixture) obtained in Synthesis Example 1 above in 10 g of benzene. It was applied to a quartz substrate by dip coating in an argon atmosphere. When the coated substrate was evaporated in an argon atmosphere and then heated at 500 ° C. for 5 minutes, a silicon film having a metallic luster remained on the substrate. The thickness of this silicon film was 1,500 angstroms. When the ESCA spectrum of this silicon film was measured, a peak attributed to the Si _2p orbit was observed at 99 eV. From the Raman scattering spectrum of this silicon film, it was 100% amorphous. When this amorphous silicon film was irradiated with XeCl excimer laser (308 nm) in nitrogen at 300 mJ / cm ² , the irradiated part turned yellow. When the ESCA and the Raman spectrum were measured for the yellow laser irradiation part, no change was observed in the ESCA, but it was found that a sharp peak appeared at 520 cm ⁻¹ in the Raman spectrum and that it was polysilicon. The ESCA spectrum is shown in FIG.
[0021]
Reference example 2
Using the amorphous silicon film obtained by coating and baking in Reference Example 1 above, the laser irradiation atmosphere was changed from nitrogen to air, and the others were irradiated in the same manner as in Example 1; changed. In the ESCA spectrum of this colorless and transparent portion, a peak attributed to Si _2p orbital was observed at 106 eV, and simultaneously a peak attributed to O _1s was observed at 536 eV, and the elemental composition ratio of silicon and oxygen was SiO ₂ . FIG. 2 shows the ESCA spectrum of the colorless and transparent part.
[0022]
Reference example 3
Using a commercially available plasma CDV device, a mixed gas of monosilane gas and argon gas (5% by volume of monosilane) is supplied at a flow rate of 150 sccm as a silicon source gas under a reduced pressure of 0.1 Torr in a 25 watts RF plasma. A bronze-colored silicon film having a thickness of 600 angstroms was deposited on a quartz substrate heated to 450 ° C. This silicon film was an amorphous silicon film from ESCA and Raman spectra. When this amorphous silicon film was irradiated with 230 mJ / cm ² of a XeCl excimer laser having a wavelength of 308 nm in nitrogen, the irradiated portion turned yellow. When the ESCA and the Raman spectrum of this laser irradiation part were measured, in ESCA, only a sharp peak was observed at 99 eV, and no peak was observed at 106 eV attributed to SiO ₂ . In the Raman spectrum, a sharp peak was observed at 520 cm ⁻¹ , and the crystal was a polysilicon with a crystallization rate of 95%.
[0023]
Comparative Example 1
The laser irradiation atmosphere of Reference Example 3 was changed from nitrogen to air, and the other was irradiated with 230 mJ / cm ² of XeCl excimer laser having a wavelength of 308 nm in the same manner as Reference Example 3 . The irradiated part turned yellow just as in Reference Example 3 . The results of measuring ESCA and Raman spectrum for this laser irradiated part were the same as those obtained in Reference Example 3 , and no peak attributed to SiO ₂ was observed.
[0024]
Reference example 4
A solution was prepared by dissolving 4 g of the polysilane compound (mixture) obtained in Synthesis Example 1 in 10 g of toluene. It was applied to a quartz substrate by spin coating in an argon atmosphere. When this coated substrate was heated at 500 ° C. for 5 minutes in an argon atmosphere, a metallic silicon film remained on the substrate. The thickness of this silicon film was 750 angstroms. When the ESCA spectrum of this silicon film was measured, a peak attributed to the Si _2p orbit was observed at 99 eV. From the Raman scattering spectrum of this silicon film, it was 100% amorphous. When this amorphous silicon film is irradiated with 300 mJ / cm ² of XeCl excimer laser (308 nm) in air through a mask having a desired pattern, the irradiated part becomes transparent, and the same pattern as the mask of the transparent part and the opaque part was gotten. As a result of microscopic observation of the irradiated part that became transparent by laser irradiation, no film abnormality such as cracks was observed, and the film was a high-quality transparent film. The thickness of this portion was 750 angstroms. When the ESCA spectrum was measured, a peak attributed to the Si _2p orbital was observed at 106 eV and a peak attributed to the O _1s orbital was observed at 536 eV, and the elemental composition ratio was SiO ₂ . Further, the surface state in the vicinity of the boundary between the irradiated part and the pattern substrate having the non-irradiated part was measured by α-step (manufactured by Tencor Instruments), and was almost flat.
[0025]
Example 1
A non-irradiated portion (amorphous silicon) of the amorphous silicon / silicon oxide pattern obtained in Reference Example 4 was further irradiated with a laser in an inert atmosphere to form a polysilicon / silicon oxide pattern.
When the surface state of the front plate was observed by α-step, it was completely flat as in Reference Example 4 . FIG. 3 shows a chart of α-step at this time.
[0026]
Example 2
A solution was prepared by dissolving 2 g of the polysilane compound obtained in Synthesis Example 1 and 2 g of the polysilane compound obtained in Synthesis Example 2 in 36 g of toluene. Using this solution, a silicon film having a metallic luster having a thickness of 1500 angstroms was formed in the same manner as in Reference Example 1. This silicon film was 100% amorphous from the Raman spectrum. When this amorphous silicon film was irradiated with an NdYAG laser having a wavelength of 532 nm in a nitrogen atmosphere at 250 mJ / cm ² , the irradiated portion turned yellow. From the measurement results of the ESCA spectrum and the Raman spectrum, it was found that the yellowing portion was polysilicon having a crystallization rate of 80%. Furthermore, when this substrate was irradiated with a 532 nm NdYAG laser at 300 mJ / cm ² in an air atmosphere, the irradiated portion became colorless and transparent. When this colorless and transparent part was analyzed by ESCA, a peak attributed to the Si _2p orbit was observed at 106 eV and was SiO ₂ . The substrate thus obtained was composed of an amorphous silicon portion, a polysilicon portion and silicon oxide in the same plane. When the surface state of this substrate was observed by α-step, it was almost flat as in Example 1 .
[Brief description of the drawings]
1 is an ESCA spectrum diagram of a polysilicon film in Reference Example 1. FIG.
2 is an ESCA spectrum diagram of a colorless and transparent portion (silicon oxide) in Reference Example 2. FIG.
3 is a view showing the flatness of the surface of a film made of polysilicon / silicon oxide obtained in Example 1. FIG.

Claims (7)

General formula SinRm
Here, R is a hydrogen atom or a halogen atom, n is an integer of 3 or more, and m is an integer of n to 2n.
An amorphous silicon film obtained by applying a polysilane-containing composition represented by formula (1) to the support surface and then subjecting to light and / or heat treatment is phototreated through a mask pattern in an oxygen-containing atmosphere, and then inert. A method for forming a pattern made of silicon oxide and polysilicon, characterized by performing an optical treatment in an atmosphere. General formula SinRm
Here, R is a hydrogen atom or a halogen atom, n is an integer of 3 or more, and m is an integer of n to 2n.
An amorphous silicon film obtained by applying a composition containing polysilane represented by formula (1) to a support surface and then subjecting to light and / or heat treatment is phototreated through a mask pattern in an inert atmosphere, and then contains oxygen. A method for forming a pattern made of silicon oxide and polysilicon, characterized by performing an optical treatment in an atmosphere. General formula SinRm
Here, R is a hydrogen atom or a halogen atom, n is an integer of 3 or more, and m is an integer of n to 2n.
An amorphous silicon film obtained by applying a polysilane-containing composition represented by formula (1) to the support surface and then subjecting to light and / or heat treatment is phototreated through a mask pattern in an oxygen-containing atmosphere, A method of forming a pattern made of amorphous silicon, silicon oxide, and polysilicon, wherein the irradiated amorphous silicon film portion is subjected to light treatment through a mask pattern in an inert atmosphere. General formula SinRm
Here, R is a hydrogen atom or a halogen atom, n is an integer of 3 or more, and m is an integer of n to 2n.
An amorphous silicon film obtained by applying a composition containing polysilane represented by the following formula to the surface of the support, followed by light and / or heat treatment, is light-treated through a mask pattern in an inert atmosphere, and then is not irradiated with light. A method for forming a pattern made of amorphous silicon, silicon oxide, and polysilicon, wherein the amorphous silicon film portion is subjected to light treatment through an mask atmosphere in an atmosphere containing oxygen. A pattern composed of silicon oxide and polysilicon is composed of a polysilicon region and a silicon oxide region, and a fixed pattern is formed in these two regions, and the surfaces of these two regions form a continuous and coplanar surface. The method according to claim 1 or 2 , characterized in that: A pattern composed of amorphous silicon, silicon oxide and polysilicon is composed of a polysilicon region, a silicon oxide region and an amorphous silicon region, and a fixed pattern is formed in these three regions, and the surface of these three regions is 5. A method according to claim 3 or 4 , characterized in that it forms a continuous coplanar surface. The method according to any one of claims 1 to 4, an amorphous silicon film is doped with phosphorus atoms or boron atoms.

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